Disazo dyestuff.



. UNITED STATES PATENT OFFICE.

AUGUST LEOIPOLD LASKA, OI OFFENBACH-ON-THE-MAIN, GERMANY, ASSIGNOR TOCORPORATION OF CHEMISCHE FABRIK GRIESHEIM-ELEKTRON, 0F FRANKFORT-ON-THE-MAIN, GERMANY.

DISAZO DYESTUFF.

No Drawing.

with one molecule of 2.8-amino-naphthol-6- sulfonic acid in acidsolution and one molecule of a metadiamin or meta-aminophenol. Thesedyestuffs dye cotton reddish shades, which after combination withdiazotized ara-nitranilin on the fiber change into red ish-brown shadesfast to washing and leaving after being discharged a pure white.

In order to illustrate the new process more fully the following exampleis given the parts being by weight: 22.4 parts of the sodium salt oftoluylenediamin sulfonic acid dissolved in 300 parts of water are cooledwith ice and diazotized with 14 parts of sodium nitrite and ()5 parts ofhydrochloric acid (20 B.). An ice cold aqueous solution of 23.9 parts of2.8-amino-naphthol-(isulfonic acid neutralized with sodium carbonate isadded. When the intermediate product is formed a solutionuof 11 partsmeta-phenylenediamin is added andthe mix ture is stirred for twelvehours. Then the solution is rendered neutral by sodium carbonate, heatedup to 7 0 C., and the coloring matter preci itated by addition of commonsalt. The yestutl' forms a dark-brown owder and dissolves inconcentrated suluric acid with reddish Bordeaux color, in water withbrownish-orange color. The aqueous solution is not altered by additionof caustic soda l ye,.by addition of hydrochloric acid the dyestutl' isprecipitated in form of reddish-brown flakes. It dyes cotton red shadeswhich after combination with diazotized paranitranilin on the fiberchange into reddish-brown shades fast to washing and leaving after beingdischarged a pure Specification of Letters Patent.

Application filed July 15, 1910. Serial No. 572,098.

Patented Jan. 24, 1911;

white. In analogous manner the formation of dyestufl may be performed byusing other meta-diamins, for instance meta-toluylenediamin. Thedyestutl' with mcta-aminophenol in second place givesreddish-yellowbrown shades after combination with diazotizedpara-nitranilin'on the fiber.

Now what I claim and desire to secure by Letters Patent is thefollowing:

1. The process for the production of new disazo dyestuil's consisting incombining the tetrazo compound of the toluylenediamin sulfonic acid withone molecular pro ortion-of 2.8-aminonaphthol-(S-sulfonic aci in acidsolution and with one molecular proportion of a metadiamin.

2. As new articles the dyestuffs obtained by combining the tetrazocompound of the toluylenediamin sulfonic acid with one molecularproportion of 2.8-aminonaphthol-ti-sulfonic acid in acid solution andwith one molecular proportion of 0. metadiamin which dyestufl's form adark-brown powder dissolving'in concentrated sulfuric acid withbordeaux, in water with brownish to reddish-orange color, the aqueoussolution of which is not changed by addition of caustic soda lye, thedyestutt being precipitated in form of reddish-brown flakes by additionof hydrochloric acid.

3. The process for the production of new disazo dyestufi' consistin incombining the tetrazo compound of to uylenediamin sulfonic acid with onemolecular proportion of 2.8-uminonaphthol-G-sulfonic acid in acidsolution and with one molecular proportion of meta-phenylenediamin.

4. As new article the dyestufl obtained by combining of the tctrazocompound of to-' luylenediamin sulfonic acid with one molecularproportion of 2 .8- an1inonaphthol-6-sulfonic acid in acid solution andwith one molecular proportion of metal-phe- I nylenediamin, whichdyestufi' forms a darkbrown powder dissolving in concentrated fast towashing and leaving after being dissulfuric acid with reddish bordeaux,in charged a pure white. 7 Water with brownish-orange color, theaque-Intestimony, that I claim the foregoing. ous solution of which is notchanged by adas my invention, I have signed m name in 5 dition ofcaustic soda lye, the dyestufi bepresence of two witnesses, this fi thday of 15 precipitated in form of reddish-brown July 1910. a

es by addition of hydrochloric acid and AUGUST LEOPOLD LASKA, dyeingcotton red-shades which after co'm-- Witnesses: bination with diazotiaedpara-nitranilin on EVA SAT'ILER,

0. the fiber changes into reddish-brown shades HERMANN WEIS.

